Prompted by fears of an impending invasion of Britain and the Empire, the organisation was founded as a field intelligence corps on a romanticised conception of the "frontier" and imperial idealism. Headquartered in London, branches of the Legion of Frontiersmen were formed throughout the empire to prepare patriots for war and to foster vigilance in peacetime. Despite persistent efforts, the Legion never achieved much official recognition.

Casualties in the First World War devastated the Legion of Frontiersmen, and except for a brief resurgence in the interwar period, a series of schisms and sectarianism prevented attempts to reinvigorate the movement. In the late 1930s, the Legion of Frontiersmen in Canada was formally affiliated with the Royal Canadian Mounted Police, but after a schism split within the Canadian Frontiersmen, the RCMP severed formal ties.[2] Various Legion of Frontiersmen groups still exist throughout the Commonwealth, but as a whole, it has been unable to define its niche in the post-imperial world.

The earliest official description of an authorized uniform for a Canadian unit is noted in The Frontiersman, (December 1912, page 223) describing Vernon and Okanagan Command’s uniform as follows: “Shirt Tunic – To be of substantial material, colour navy blue; leather buttons; nickel shoulder chains. Breeches or (Trousers) – Any shade of khaki. Footwear – Brown leather; any combination that affords cover as high as the calves. Headdress – Straight brim Stetson, any shade of brown, with leather band and regimental crest and monogram. Accessories – Brown leather fringed gauntlets; silk blue and white “bird’s-eye” neckerchief; regulation LF holster.”[7]

The Current dress uniform is generally centred around a cavalry blues theme - complete with shoulder chains. This is either worn with a russett-coloured beret, an SD cap or a colonial-pattern 'Lemon Squeezer' (Smokey Bear hat). Jodhpurs and riding boots are worn by the 'Legion of Horse' when 'mounted'.

Different branches of the legion, in different parts of the Commonwealth award medals within their units and occasionally to external branches, commands or units.[8] These medals are not part of any government honours system and should not be treated or claimed as any kind of official military decoration. These medals are much like those of the Freemasons,[9] valued only by members. The Australian Division awards a decoration called the "Australian Medal of Merit" (internally used post nominal letters AMM)[10] that has caused controversy where it has been implied by an occasional recipient that it is a government-endorsed, official medal.[11]